Part 2: Management of Ewes during middle trimester of pregnancy
Pregnant ewes are more efficient than dry ewes in picking up weight and their requirements for supplements in this phase is not much higher.
Deficiencies can be prevented by using licks. Lambs grow only about 20% of their body birth weight in the first 3 1 /2 months They therefore do not have a much higher nutritional requirement in middle 1/3 of pregnancy.
Feeding a lick will usually be adequate to keep the body weights of ewes constant or to prevent a loss of more than 5% of body mass or 1 point of Body Condition Score in the 2nd and 3rd month of pregnancy. Lick intakes of 50 to 70 gram per day is usually sufficient. Urea in the lick at this stage should not cause too much problems. Twin ewes will benefit from being placed in a separate flock immediately following scanning. These ewes usually weigh more than the flock average and they walk slower and tend to lag behind the flock.
They therefore loose condition if they try to keep up with the rest of the flock. Triplet carrying ewes have a much bigger problem. The growth of the foetus in the last third of pregnancy compresses the rumen and therefore these ewes should start receiving more concentrated feed as soon as possible. This will allow them to increase their fat reserves in late gestation and early lactation. Two-tooth ewes are still growing and it will assist them if they are kept in a separate group so that they can be fed supplements.
They have a higher protein requirement and they should receive at least 50% of their requirement in the form of natural protein supplements. Sunflower or Cottonseed oil cake meal, HPC 36 (urea free), or fishmeal can be included in their lick. Their intake should be higher than that of mature ewes and the salt content should be reduced.
Maiden ewes who are mated before they cut 2-teeth the mating should be planned that the ewes cut teeth in the middle 1 /3 of gestation (mate at 10 to 11 months). Ewes experience nutritional stress while cutting teeth and mid gestation will have the least problems.
It is extremely important to provide lick supplements while cutting teeth. Financial analysis of the practice to mate ewes at 7 months usually indicate that it is not a viable practice and that mating at 11 months in an 8 monthly cycle or at 18 months in an annual system remains the best option.
In the next article, the focus will be on the last pregnancy phase.
By Dr Johan A. van Rooyen M.Med. Vet. Specialist Veterinarian
Steynsburg Animal Hospital Eastern Cape
